The intervertebral disk is a disk with fibrous bands occupying the space between two vertebrae. The anatomy of the disk provides a cushion to allow motion, limit motion and provide space, distancing the vertebra off the nerves and compressible tissue. Part of the vertebrae are bony blocks, which, when stacked one upon the other, form the anterior portion of the spine. The fibrosus band includes an outer annulus fibrosus which surrounds an inner nucleus pulposus. Annulus fibrosus, as referred to herein, is the marginal or peripheral portion of an intervertebral disk. Intervertebral disks are prone to injury. Due to the low blood supply to this area, intervertebral disks are slow to heal, and may not materially heal. When the annulus fibrosus is torn, or punctured, the nucleus pulposus can leak or migrate from the annulus fibrosus. The nucleus pulposus is a substance of jelly like consistency found in the center of an intervertebral disk and flows from the associated annulus fibrosus when the annulus fibrosus is ruptured or prolapsed.
The effect of a ruptured or prolapsed annulus fibrosus may result in spasm, and neurological compromise, such as the compressed nerve and other compressible soft tissues, i.e. arteries, veins. Degeneration of the condition may increase overtime, resulting in chronic and debilitating pain. The condition is usually disabling.
Suppressive measures include steroidal injection, removal of the nucleus pulposus, and fusion either by donor bone, coral or by metal bracing. If disk removal is performed, a healthy part of the disk is often taken, eradicating the function of the joint, and accelerating the degeneration of adjacent segments of the body, as the body attempts to stabilize. This approach frequently leaves the patient immunologically and structurally compromised if not permanently disabled.
Isolated treatment to only the damaged structures employing the most non-invasive procedure possible is preferred. This approach allows as much of the healthy tissue as possible to remain, and to retain normal neurological function. While the offending material can be removed, the material must be replaced with a material which will perform the function formerly performed by the material removed. A need exists for a process which limits the material removed from the intervertebral disk, and which replaces the material so removed with a composition that is physiologically acceptable to the human body, and which allows the intervertebral disk to retain motion and characteristics of normal joint function, including cushioning the joint as compression is introduced from the stacking of the vertebrae. The thermoplastic material must be pliable in its application, and non-flowing after replacement.
In addition, many patients suffer from scoliosis or lateral curvature of the spine. The most common remedy at the present time is the fusion normally by donor bone or metal bracing which oftentimes is not successful or only partially successful. Pain normally accompanies scoliosis and pain suppressants may result in an undesirable chemical dependency in some instances. A need exists to correct the abnormal curvature of the spine without utilizing fusion techniques applied to the spine.